While the world watches the pomp and circumstance of Inauguration Day unfolding at the U.S. Capitol, an intricate and highly orchestrated move unfolds behind the scenes at the White House.

Every four to eight years, over the course of just a few hours, a few dozen members of the White House staff move out the belongings of the outgoing first family and move in the belongings of the new first family.

This Inauguration Day, President Joe Biden and first lady Jill Biden will wake up in a White House filled with their belongings and personal mementos — everything from personal photographs to their favorite foods in the kitchen.

At night, President Donald Trump and first lady Melania Trump will go to bed in a White House fully stocked with everything from their clothes to their preferred toothpaste.

“It’s an amazing day where they have five hours to move one family out and another family in,” Kate Andersen Brower, author of “The Residence: Inside the Private World of the White House,” told ABC News. “They don’t hire movers to do it. They do it themselves, so it’s an all-hands-on-deck situation where everybody on the staff pitches in and helps that day.”

The move traditionally begins in the morning, after the outgoing president and first lady say goodbye to the White House staff, the ushers, butlers, chefs and others staffing 1600 Pennsylvania Avenue.

The goodbye, held in the State Dining Room, is often an emotional one as the first family and staff have formed a bond, according to Brower, also the author of “First Women: The Grace and Power of America’s Modern First Ladies.”

During the ceremony, the White House staff present the president with the American flags that flew over the White House on the president’s first and final days in office. The flags, according to Brower, are presented in a wooden box made by the White House’s carpenters.

“The president and first lady walk around to everybody and say goodbye and hug, and sometimes people cry,” Brower said. “It’s a really human moment in what seems like a very formal day full of pomp and circumstance.”

Once the president and first lady depart the White House for the inauguration ceremony, a frenzy of activity begins inside.

The to-do list includes everything from switching out mattresses and bedding to moving furniture, moving boxes, refilling refrigerators, stocking preferred toiletries, doing paint touch-ups and filling closets.

“There’s a moving van that is positioned in one direction to take the belongings of the outgoing president and first family to leave the White House,” Anita McBride, who served as chief of staff to first lady Laura Bush, told ABC News eight years ago, on the eve of the first Trump administration. “And then you have moving vans and trucks that are pulling in from the other side of the driveway on the south side of the White House that will be ready to unload all of the belongings of the new family.”

No outside movers are hired to execute the move between first families due to security reasons.

Instead, the process is overseen by the White House chief usher, a historically non-political role that, more recently, has changed with new administrations, according to Brower.

“They’re really the general managers of the White House,” she said, noting that one chief usher, Gary J. Walters, worked in the role for decades, from 1986 to 2007, serving four different presidents.

When Barack Obama became president, he hired a new chief usher, the first woman in the role, and the subsequent Trump and Biden administrations also each hired a new usher versus keeping their predecessor’s hire in place, according to Bower.

“‘It’s a position held in really high esteem, at least historically it has been inside the White House,” Brower said. “You’re the boss, and when there’s a problem among the 100 staffers, you’re the one that’s going to hear about it.”

During the Clinton family’s move into the White House in 1993, for example, it was the chief usher who had to deal with finding then-first lady Hillary Clinton’s inaugural gown that was lost during the move, according to Brower.

The chief user is also the person who begins to prepare for the Inauguration Day move as far back as when the parties formally nominate their presidential candidate. At that time, according to Brower, the usher starts reaching out to the nominees’ inner circles to learn more about their likes and dislikes.

Once a candidate is elected president, the chief usher surveys the president-elect’s advance team to get details like their favorite brand of shampoo, preferred pillows and more.

Donald and Melania Trump are unique among first families in that they are returning to the White House after four years away.

Since White House staff members tend to stay in their jobs for decades, many butlers, chefs, housekeepers and more from the Trumps’ first term will be working with them again.

“There’s been a four-year break, but he’ll be back, and they will know exactly what he wants stocked,” Brower said. “I mean, they know everything, so that makes it a lot easier for the staff.”